Well drilling system



Aug. 14, 1934. LCl SMH-H 1,970,253

WELL DRILLING SYSTEM Filed Deo. 4, 1929 2 sheets-sheet l 35 A TTORNEY Aug. 14, 1934. J. c. SMITH WELL DRILLING SYSTEM Filed Dec. 4, 1929 2 Sheets-Sheet 2 James BY INVENTQR Conrad ,5m/71 ATTORNEY Patented ug. 14 1.934

vUNl'rls) .STATES PATENT oFFlcg malais.

This invention relates to a system for drilling oil wells, and especially in which use is made dur.- ing the'process of drilling, of a circulating fluid through the drilled portion of the well. The utility of such a circulating uid (or mud fluid as it is generally termed) is now well understood, as well as the general process of rotary drilling in l which it is used. Accordingly, it is unnecessary to detail very carefully this system of drilling, be-

yond mentioning that the fluent medium, among other uses. serves to carry 0E the drilling waste, as well as to maintain the drill cool.

It is also well-known at this time that the drill has a tendency to slant oil from a substantial vertical position. This causes the well to be drilled out of plumb, which for obvious reasons is highly undesirable; it causes unnecessary wear oi the drill stem, necessitates frequency surveys, and often results in twist offs. All these factors very materially increase the cost of drilling.

It is one of the objects of my invention to make it impossible to continue drilling, once there is a material deviation of the drill 'from vertical position.

I accomplish this result by ensuring that the circulation of the fluent medium in the well is substantially stopped. 'I'his immediately loads the drill to such an extent that no further cutting can be accomplished. Accordingly, it is 'another object of my invention to provide a system in which the mud fluid circulation is controlled in accordance with the directional characteristic of the drill hit. v

From another aspect, I may state that in a broad sense, my invention contemplates a system in which the circulation of the uent material in an earth bore during the process oi drilling is automatically controlled.

My invention possesses many other advantages, and has other objects which may be made more easily apparent from a consideration of one-eni-` bodiment of my invention. For this purpose l' have shown a form in the drawings accompanying and forming part of the present specification. l shall-now proceed to describe this form in de.

t tail, which illustrates the general principles of my invention; but it is tobe understood thatthis shortened to save space, in which my invention v` can be incorporated;

mi., 255ml.)

Fig. 2 is a longitudinal section of a portion of the drill stem in which is located the apparatus that embodies my invention; v

Fig. 3 is an enlarged sectional view, taken along plane 3--3 of Fig. 2;

Fig. 4 is an enlarged sectional view, taken along plane iid oil Fig. 2;

Fig. 5 is an enlarged sectional view, taken along plane 5 5 of Fig. 2;

Fig. 6 is an enlarged section, similar to Fig. 2. but illustrating the functioning ofthe apparatus when the drill has deviated substantially from a vertical direction; and A Fig. 'I is a detail section on a still larger scale, showing the main operating parts of the invenftion.

in Fig. l there is shown an earth bore 11 of indefinite length, and shown in this instance as having a casing l2 of conventional structure. This casing in thisinstance extends nearly to the bottom of the bore 1l, but it is apparent that such a casing can be omitted if desirable. A

drilling device 13 is shown as operating on the bottom 'of the bore ll. This device can be any form vof drill that operates by rotation; I show it to be a common form of fish tail bitl but other.

forms could obviously be nsed.

This bit 1?; is fastened to a string oi pipe in the usual manner, and is shown as having a transverse opening 14 that establishes communication from inside the drill stem into the bore 1l. The stem has a nipple l5 at its lower end to which is coupled the drill i3. This nipple 15 is fastened into the bottom of the length oi pipe or section ld.

This section it is in turn coupled to a number -of lengths oi pipe, the combined length of which is sufficient to place the top section 1'! in operative relation to a rotatable kelly bar l. This bar is shown as operated in a lconventional man= ner, by being splined in a rotating table 19, driven as by gearing 20 from any convenient source ci' power. 'I'he top .of kelly bar 1d connects 'to a conventional swivel 2l, having an eye 22 for supporting the drill stem assembly byy a derrick hooi; 23.

A mud iluidcirculation is provided for, as by the aid of a pump 2d. This pump-has` a flexible conduit connection 25 forming an outlet for the pump, and passing mud fluid into the top of the bar 18 via the swivel 21. This fluid extends down through the drill stem and is forced through aperture 14 into bore 11. Near the top of the bore 11 there is a conduit 28 leading the mud fluid into` a receptacle or reservoir 27. From this reservoir extends an inlet pipe 28 for pump 24.

It is apparent that the course of the uent medium is downward in the drill stem, and upward to conduit 26. This medium is sumciently fluent to be properly treated by the pump 24. Since many oil well bores extend for thousands of feet below the earths surface, the pressure exerted by this fluent medium is quite high.

yI arrange matters in such a way that this circulation just described is substantially stopped automatically in response toa definite drilling condition; and in this embodiment of my invention, this stoppage occurs when the drill stem 16 deviates from the vertical. When this stoppage occurs, the pump 24 will labor, and the operator will be apprised of this by the difference in the hum or sound of the pump operation, aswell asby a direct gauge indication of the pump outlet pressure. At the same time, if he does not prompt- 1y stop the table 19, the drill 13 will become so heavily loaded that the mechanism will be stalled.

Thus he is prevented from drilling until he rectifies the condition existing.

To do this, hstops the pump 24 and relieves the pressure by opening a bleeder valve 28 in the outlet side of pump 24. Knowing that the stoppage of circulation is caused by the deviation of the bottom of the bore from the vertical, the driller can take steps to correct this condition, as itis otherwise impossible for him to continue his drilling. For example, he may withdraw the drill for about fifteen or twenty feet and start anew.

The arrangement is such that as soon as the pressure is released in the pump 24, the circulation of the fluent medium can be reestablished, but only in the event that the drill stem is straight.

A reference to the other figures will make clear how this control operates automatically.

Above the nipple 15 there is a vertically movable valve 29 which is normally in the position of Fig. 2 while the drilling is vertical. 'I'his position is such as to permit the fluent medium to pass down unimpeded through nipple 15 froml section 16. The dropped position of this valve closure 29 onto the top of the nipple 15 is shown in Fig. 6. In this position, the valve materially retards the circulation, as the fluent medium can pass into the drill 13 only through the restricted slanting apertures 30. The pressure of the mud fluid on top of the valve closure 30 serves to hold it in place when it is dropped. This holding-action is also increased by the friction of the mud fluid against the slanting walls of apertures 30 as the fluid squeezes through.

I shall now describe howthe valve closure 29 is permitted to drop from a locked position in response to the deviation of the drill from the vertical.

Supported inside the lower section 16 of the drill stem is a hollow capsule 31. 'Ihe supporting means can be in the form of a number of bars 32 arranged near the top and bottom of the capsule between it and the inner wall of section 16. These bars can be welded between these two parts. The top of the capsule is closed by a fluid tight cover 33. The bottom is closed by a guide member 34 threaded therein and having a vertical opening in which is guided a stem 35 that carries valve closure 29.

In order to ensure against entry of mud fluid into the capsule through the bottom thereof, this stem carries a number of piston rings 36. Furthermore, the stem passes through a packing gland 37, which has a wiper pad or gasket 38 in its .inside edge. There is a thin metal lining 39 inside capsule 31. It is in this lining that the control parts are mounted. lIt can be formed of a pair of halves, made from brass, held as by a series of screws 40, 41, 42 to the capsule 31.

Stem 35 is guided at its upper end in a collar 43 fastened in place by screws 42 in capsule 31.

In order to prevent rotation of this stem relative to the capsule, a slot and pin spline 44 can be provided between the upper part of the stem and this collar. Normally, stem 35 is urged upwardly by the aid of a tension spring 45. This spring is disposed around an enlarged portion 46 of the stem. Its upper end is anchored to collar 43, as by the provision of a grooved flange 47 fastened to the bottom of the collar. The lower end of the spring 45 is anchored around a flange 48 carried at the bottom of the enlarged portion of the stern 35. Thus this spring tends to draw the top edge of the enlarged portion 46 up against the bottom of collar 43.

I show slanting slots such as 49, 50 in flanges 47, 48 to facilitate disposal of a turn of the spring 45 around the flanges.

While the drilling is progressing normally, the valve closure 29 nevertheless has a large fluid pressure exerted on its upper surface tending to urge it to the position of Fig. 6. However, I employ a locking device that prevents this action until the lock is released automatically, as I shall hereinafter explain. I shall now describe the locking device.

Above collar 43 there are located a pair of gripper jaws 51, placed diametrically opposite each other. These jaws have rounded ends arranged to enter into a rounded groove 52 near the top of stem 35. They are pivoted in any convenient manner, as for instance in standards 53 (Figs. 5, 6, 7). They have extensions 54, which, when the jaws 51 are in gripping relation (as shown in Fig. 2) are spaced slightly apart at the top. To prevent the jaws from opening, there is a detent 58 that drops between these extensions to the position shown in Fig. 2.

While detent 58 is in this position, it is apparent that stem 35 is held against dropping. This detent is operated in a, manner that will hereinafter be described. It is sumcient for the moment to note that it is guided for vertical movement in an insulation collar 55 fastened to the inside of shell 39.

When detent 58 is lifted, as indicated in Fig. 6, so as to permit arms 54 to collapse, the jaws 51 separate, and stem 35 is free to move downward to cause the stoppage of circulation of the mud fluid. The pressure acting on the shoulder 56 of valve closure 29 will quickly urge this closure to close the opening 57 in nipple l5, and against the tension of spring 45. As soon as the pressure is relieved as by the opening of bleeder valve 28 on pump 24, the pressure abovevalve 29 will be reduced suillciently to equalize the pressures on top of and below this closure. Then spring 45 is free to act to lift the valve clear.

'I'he upward movement of stem 35 is arranged to open these arms as soon as jaws 51 are opposite groove 52. i 'I'his is accomplished by providing a wedging surface 60 at. the top of stem 35, which coacts with the inner surfaces of bars 54 to urge them apart. Tip 59 at the same time, limits the drop of detent 58 between the arms. It is thus apparent that when spring 45 is free to act, it can pull up stem 35 which then becomes automatically relocked.

in the present instance, detent 58 is electromagnetically controlled. Thus supported on collar 55 is a solenoid coil 61, and detent 58 is made from magnetic material so that when this coil is energized, the detent is pulled up by it. The circuit for the solenoid is completed in response to a definite deviation from standard drilling conditions; for example, upon a deviation vtrom the vertical. I shallY now explain how this is accomplished. A

The source of electrical energy for coil 6l is preferably a low voltage source of supply, such as a number of dry cells, which may be accommodated in a case 62 near the top of capsule 31. In order to support this case properly, a compression spring 63 is interposed between the top of the case and the cover 33; and a similar spring 64 is interposed between its lower end and an insulation collar 65. One terminal of the battery is grounded; as by'one of the springs 64, 65; and the other terminal connects as by a wire 66 (Fig. 6) to one terminal of coil 61.

The other terminal of coil 61 is connected to a contact post 67 fastened into a collar 68 of insulation. This post extends through, but is insulated from, a metal collar 68.

A pendulum arrangement is provided to ground post 67 and thus complete the solenoid circuit whenever there is a deviation beyond a set amount, of the drill section 16 from the vertical. Thus a pendulum 69 is suspended ireely at its top in a frame 76 in such a way that when the position of capsule 31 is oil vertical (as indicated in Fig. 6), its lower end swings against post 67. To ensure a good electrical contact between this pendulum (which is grounded so that it forms a terminal of battery 61), and the post, these parts can besilver plated, or other goed non-corrosive material can be used for the contact-making parts. l

Frame 70 is preferably arranged to be free to position itself, so that pendulum 69 will be at the high side of the axis of the drill when there is a deviation. .innthis way, gravity will pull the bottom of the pendulum inwardly against post 67. To accomplish this result, frame 70 is provided at its top and bottom respectively with bearings. Preferably these are ball bearings.

Thus at the top of frame 70, there is a post 71 which carries one portion of a ball race 72, the

l other portion being fastened into the bottom of a collar 73. At the bottom, the frame 76 carries a hollow post v74 through which contact post 67 passes with clearance. This hollow post in turn carries one portion of a ball race v75, the other portion being fast in metal collar 68'.

Frame 70 is so weighted that. gravity always positions it about the axis of posts 7l and 74 as to bring the pendulum side uppermost. This is accomplished by making that side of the frame which is opposite pendulum 69 much heavier than the pendulum. As shown clearly in Figs. 3 and 4, pendulum 69 can be hung on arms 76 on an axis slightly spaced from the center of the device. lThus upon deviation from vertical position, the pendulum will be urged toward the axis so as to contact with post 67 and to complete the circuit for coil 61.

in order to limit the outward movement of the pendulum 69, a guide 77 is provided, extending i'rom post 74, which embraces the lower end of the pendulum and provides an abutment 78 against which the pendulum is stpped.

Having described the details of construction of my device, a brief recapitulation of its mode of operation will now be presented. f

While the drilling is progressing in a vertical direction, pendulum 69 remains in the position of Fig. 2. The frame 70, being freely pivoted at the top and bottom on ball bearings, stays substantially immovable about its axis even while the drill stem is operated. The valve closure 29 is held raised above the top of nipple 15, by the' gripping jaws 5l engaging in groove 52.

Asvsoon as a slant or deviation from the vertical develops, as shown for example in Fig. 6, frame 70 by its weight assumes a position that carries pendulum 69 to the high side of the axis of-the stem. The pendulum now swings inwardly to make contact with the top of post 67. The coil 61 is energized. Detent 58 is pulled up from between arms 54, and jaws 51 separate. This frees stem 35 to which valve closure 29 is fastened, and this closure is urged by the mud fluid pressure to closing position on top of nipple 15, against the action of spring 45.k When the valve is thus closed, the mud fluid presses through the small openings 30, and the force developed by this pressure assistsin holding the valve closed.

The mud uid circulation is thus substantially stopped. The pump 24 labors, and the drilling force is also very greatly increased. These features serve as an indication to the operator at 'the top of the well that the circulation is very materially impeded, and if allowed to continue, this stoppage will shortly cause the drill to be seriously injured.

Accordingly, he raises the drill stem while at M0 the same time he opens valve 28' to relieve the pressure. Il'he extent which he raises the stem depends upon the axial distance between the pendulum 69 and the `drill 13; probably of the order of ten or twenty feet. When the stem is thus placed in a straight portion of the bore, pendulum 69 assumes the position of Fig. 2. it opens the circuit for coil 6l, and detent 58 is allowed to drop onto the top of arms 54. if the pressure has also been reduced byrelieving pump 24,12@ spring 45 can raise valve stem 35. .iis this stem raises, the shoulder 60 engages the lower side of arms 54 and urges them open to cause jaws 5l to enter the groove 52. At the same time, detent 58 drops between arms 54 onto the tip 59 and 1125 prevents the jaws from opening. l

The mud fluid circulation is now unimpeded. Drilling from this level can start afresh, and the drill will at this second trial, have the chance of continuing the bore undeviated.

The occurrence of any further deviation will occasion a similar cycle. i

l claim: L

i. In a system of earth bore drilling, a rotatable drilling tool, means for circulating a iluent medium fromthe top of the bore through the tool, a valve mechanism arranged to be inserted in the tool stem, for controlling the circulation of the medium, and means responsive to a deviation of the drilling operation from the vertical foroperating the valve, including a pendulum structure, and an electric circuit controlled by the structure.

2. ln a device for controlling earth bore drilling, a valve closure,`jaws for holding the valve closure in' one position, a detent for maintaining the jaws in holding position, and means responsive to a deviation of the drilling from the vertical for moving the detent to release the jaws.

3. In a device for controlling earth bore drilll ing, a valve mechanism including a valve closure. jaws for holding the valve closure in open position, a detent for maintaining the jaws in holding position, means for moving the detent to release the jaws, said closure being arranged to be urged to closing position by fluid pressure, and means capable of operating when the i'iuid pressure is released, to move the valve closure to open position and to return the Jaws to holding position.

4. In a device for controlling the circulation of a iuent medium through an earth bore during the drilling operation, a valve mechanism including a valve closure, arranged to be utilized in the bore and near the place of drilling, means for holding the closure in openvposition, means responsive to a deviation of the drilling operation from the vertical for releasing the closure, whereby fluid pressure serves to close the valve. and means for opening the valve when the pressure is reduced, and for relocking the holding means.

5. In combination with a drill shaft having penetrating means at its lower end and a rotary power device for driving said shaft; gravity controlled means associated with said drill shaft and operating in response to a deflection of said drill shaft from the vertical to give a sensible indication of. such deection, said last mentioned means being actuated by hydraulic pressure.

6. In combination witha drill pipe and a iqluid pressure system for forcing drilling fluid through said d rill pipe; gravity controlled means operated by said pressure iluid for giving a sensible indication when said drill pipe has deilected from the vertical.

7. In combination with a drill pipe and a fluid pressure system for forcing drilling iluid through said drill pipe; gravity controlled means operated by said pressure iluid for giving an audible indication when said drill pipe has deflected from the vertical.

8. In combination with a substantially vertical tube; a gravity controlled indicator in said tube for giving an vaudible indication when the tube is deflected from the vertical and pressure operated means for actuating said indicator.

JAMES CONRAD SMITH. 

